Metasurface-based functional optical splitter for a spatially parallelized dual-polarization coherent modulator.

We propose a surface-normal dual-polarization in-phase and quadrature modulator (DP-IQM) that employs a thin dielectric metasurface (MS) layer inserted on a high-speed electro-absorptive modulator array. The metasurface provides the functionalities of all the passive components necessary for a DP-IQM, including a polarization beam splitter/combiner and an interferometric circuit, to a normal-incident beam. A dielectric metasurface composed of silicon nanoposts is designed and fabricated to experimentally demonstrate polarization and beam splitting functionalities with a phase error of less than 0.

Association of overtime work duration with oral health-related quality of life in Japanese workers.

Purpose: Overtime work is associated with a risk of developing various diseases, including oral diseases. Oral Health-Related Quality of Life (OHRQoL) is a more comprehensive assessment than those of individual diseases and can be affected by longer working hours.

Methods: This cross-sectional study examined the association of overtime work duration with OHRQoL.

Comparative analysis of speckle-based single-pixel imaging using uniform and non-redundant optical phased arrays.

An optical phased array (OPA) is a compact high-speed wavefront modulation device that is promising for next-generation optical sensing systems. In particular, speckle-based single-pixel imaging (SSPI) using OPA is an attractive scheme since precise tuning of optical phases is unnecessary. In this work, we present a comprehensive analysis of SSPI using an OPA with phase shifters by comparing two classes of OPAs: uniformly spaced OPA (UOPA) and non-redundant OPA (NROPA).

Compact symmetric polarization rotator-splitter on InP.

Symmetric polarization rotator-splitter (PRS) is proposed and experimentally demonstrated on InP for the first time. Instead of integrating a mode-selective splitter, we employ a symmetric multimode-interference (MMI) splitter at the output of an adiabatic taper section to extract the linear superpositions of the transverse-electric (TE) and the transverse-magnetic (TM) components of the input signal. As a result, the entire device functions as a PRS with its basis on the S-S plane of the Poincaré sphere, whereas we can fully eliminate complicated asymmetric structures that are challenging to fabricate on InP.

Efficient InGaAsP MQW-based polarization controller without active-passive integration.

Carrier-injection-based efficient polarization controller with a strained InGaAsP multiple-quantum-well (MQW) layer is demonstrated on a regrowth-free InP platform. We employ a straight-line device configuration by cascading an asymmetric polarization rotator (PR) to provide a fixed polarization conversion and a polarization-dependent phase shifter (PD-PS) to enable tunable polarization rotation. Based on a novel design concept, both the PR and PD-PS sections are integrated monolithically without active-passive integration.